Who will fill DeMint's Senate seat?

In a surprising twist of political fortunes casting a deep impact on the South Carolina political landscape, Sen. Jim DeMint (R-SC) announced today that he would resign his U.S. Senate seat to take over the helm of the Heritage Foundation, a conservative think tank.

Not surprisingly, DeMint's announcement has set off a flurry of speculation over whom Republican Gov. Nikki Haley would choose to replace the Tea Party-backed DeMint.

The Palmetto State will now hold three marquee statewide contests in 2014 -- two Senate seats and the governorship -- creating potential opportunities for several South Carolina Republicans.

"It puts us right in the middle of the political epicenter," said former South Carolina GOP Chairman Katon Dawson. "It will showcase how diverse of a field we have and which we don't get enough credit for," he said.

The big question remains whether Haley will opt to name a "place holder" (in the light of Paul Kirk in Massachusetts or Ted Kauffman of Delaware) who publicly announces intentions not to seek the special election in 2014, and run herself for the open-seat instead of re-election for governor. Or does she choose a successor to DeMint who will have the resources and credibility to defend the seat in a special election in two years?

"Whether it's a guardian or a replacement who defends the seat in two years, we have a deep bench of conservative candidates in South Carolina," said Dawson. "Gov. Haley will avoid the noise, make the right choice and it will be a strong decision," he said.

If Haley chooses the second option, three potential placeholders are Deputy Chief of Staff Ted Pitts (a former SC legislator), Nathan Ballentine (a current member of the South Carolina assembly with strong ties to Haley), and former Attorney General Henry McMaster (who competed against Haley for governor in 2010).

Republicans familiar with Haley's thinking don't believe that shadow ideology of either DeMint or Sen. Lindsey Graham will play a role in her selection.

"She's going to pick someone who lines up with her own philosophy rather than a clone of DeMint or Graham," the GOP source said.

There has been speculation in recent weeks that Lindsey Graham -- who is known to seek compromise and broker deals in the Senate and who recently said he could violate the Grover Norquist pledge -- would face a primary opponent. DeMint's announcement possibly changes the political landscape much to Graham's benefit.

"I don't think there is a happier person in South Carolina right now, than Lindsey Graham," said Joel Sawyer a South Carolina Republican operative. "I don't think anyone saw this coming," he said.

If he is forced to face a primary, a field of modest candidates taking aim at Graham will be better for the two-term incumbent versus a strong credible challenger jockeying to face him one on one. The conventional wisdom suggests than a serious well-resourced candidate will likely choose to seek the open seat than battle Graham in costly primary.

U.S. Reps. Tim Scott and Mick Mulvaney have also been mentioned as possible contenders for an open Senate seat or as a candidate for governor should Haley run for the Senate seat.

"He is definitely interested in running for the Senate," said a Mulvaney ally who requested anonymity to speak more candidly. "He has expressed interest about seeking the seat if Sen. DeMint were to retire and now we will wait to see who the governor appoints and assess the race after she's made a decision," they said.

"Mulvaney is a rock star in South Carolina," Dawson said. "He took on a budget chairman who was in office for 28 years [Democrat John Spratt], and no one thought he could win."